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Is the amperage of a breaker for total amps combined or on each leg?
Wiki User
∙ 14y ago
The breaker will trip at the amperage notated on the breaker. If it's 100A...it will trip at or around 100A. It does not matter if that breaker is physically tied to another 100A breaker.
To understand this, imagine that you remove the mechanical tie from the two-pole breaker. Now you just have two 100A breakers. In actuality, you always had two 100A breakers. The mechanical tie does not change that.
If you then powered two, separate 120 volt devices from the two breakers, each breaker would allow 100 amperes to pass to each of the devices before tripping.
So why are they tied together? That is done when the two-pole breaker is to be used to power a 240 volt circuit. In AC current, electricity flows in both directions. In a 120 volt circuit, it flows "out" toward the device via the hot (generally the black wire) and "back" via the neutral (generally the white wire). Then the cycle reverses. It does this 60 times per second (60Hz). The amperage in the hot and neutral wires are the same (in the perfect world). Only the hot wire is connected to the breaker.
In a 240 volt circuit, there is no neutral wire. You are using two "legs" of 120 volts each that are 180 degrees out of phase with each other. In other words, as leg 1 is flowing "out", leg 2 is flowing "back". Because they are out of phase, the potential difference is twice the voltage of each line or 240 volts. The current flows out and back at the same 60 Hz but this time via the two hot wires (generally black and red). Each of these hot wires are connected to the two terminals of the two-pole breaker.
Due to mechanical tolerances, one breaker will most likely trip before the other. Therefore, if the rated current, (100 amps), is exceeded on either breaker, that breaker will trip and the other breaker will trip via the mechanical tie. This ensures that all power to the outlet is disconnected. If you removed the tie and only one breaker tripped, there would still be 120 volts connected to the outlet.
In summary, each leg of a single, double (2 phase) or triple (3 phase) breaker is capable of allowing the amount of current denoted on the breaker. The connected circuit, regardless of voltage is protected from exceeding that amperage.
David B.
Josiah Crooks
Wiki User
∙ 14y agoIt will have 2 50 amp legs for 240V, as each "leg" needs to be equal in a 240 volt circuit. An easy way to think of 240 volt is as 2 110/120 volt lines, you would need a single 50 amp breaker for single phase 110/120.
Wiki User
∙ 14y agoCombined. A two-pole 100A breaker will draw 50A on each leg. A three-pole 100A breaker will draw 33A on each leg.
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People have funny concepts about electricity , the above is totally false. A two pole 100A breaker will draw 100A on each leg. A three pole 100A breaker will draw 100A on each leg. The number that is marked on every breaker is the amperage that the breaker is designed to trip at. Sheer reason should tell you that if you wanted to protect a 240 volt load at 50 amps you would not install a breaker that has 100 amps marked on it.
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Is 60 amp breaker good for 225 stick welder?
The 225 amps is the secondary output amperage. Look on the machines nameplate to find the input amperage. It is that amperage that is needed to size the feed wire and there the breaker size. When you find that amperage you may want to re question the breaker size.
Can you use a 25 amp double pole breaker for a 240 heavy duty whirlpool dryer.?
The recommended breaker for dryers is 30 amps. If you want to do the calculation to see if a 25 amp breaker will work use the following formula. W = A x V, A = W/V. Find the wattage of the unit and divide it by 240 volts to get the amperage. If the amperage is under 25 amps then the breaker will work. If the amperage is over 25 amps then a 30 amp breaker on #10 wire will be needed.
How many amps doe it take to trip a 20 amp breaker?
20 amps on the circuit will trip it unless it is is broken. Then it may trip with a lower current or not at all... Any resistance added to the circuit from a bad or dirty connection will add to the total current causing it to trip sooner than expected.
What size breaker do you need for a well pump?
A breaker is based on the amperage that is drawn by the pump motor load. Find the full load amperage of the motor. The wire fed from the breaker has to be rated at 125% of the motors full load amperage. The breaker for motors have to be over sized, usually 250% of the motors full load amps.
What is the amperage rating of the mission essential power MEP circuit breaker of the secondary distribution center?
200 amps
If a breaker is rated for 30 amps and is 2 poles is it ok to put an appliance that draws 50 amps?
The number that is on a breaker is the amount of amperage that the breaker can deliver before it trips. This is the same regardless of how many poles the breaker is.
Is 60 amp breaker good for 225 stick welder?
The 225 amps is the secondary output amperage. Look on the machines nameplate to find the input amperage. It is that amperage that is needed to size the feed wire and there the breaker size. When you find that amperage you may want to re question the breaker size.
Can you use a 25 amp double pole breaker for a 240 heavy duty whirlpool dryer.?
The recommended breaker for dryers is 30 amps. If you want to do the calculation to see if a 25 amp breaker will work use the following formula. W = A x V, A = W/V. Find the wattage of the unit and divide it by 240 volts to get the amperage. If the amperage is under 25 amps then the breaker will work. If the amperage is over 25 amps then a 30 amp breaker on #10 wire will be needed.
How many amps doe it take to trip a 20 amp breaker?
20 amps on the circuit will trip it unless it is is broken. Then it may trip with a lower current or not at all... Any resistance added to the circuit from a bad or dirty connection will add to the total current causing it to trip sooner than expected.
If I want to know the amperage for each outlet on a power strip can I simply divide the total amps by the number of outlets?
If you want to know the amperage for each outlet on a power strip then check the nameplate current on the device that is plugged into that outlet on the power strip. Power strips usually have their own breaker that will trip at 15 amps. If you load the strip to its maximum capacity there is a good chance that it will trip before the distribution circuit breaker will trip. You can not simply divide the total amps by the number of outlets as each device will have a different amperage and depending on where it is plugged into the strip these amperage's in a set position will change.
Can you run a 2 kw convector heater through a 25 amp trip switch at 240 volts?
Yes, the total amperage load of a 2000 watt heater at 240 volts is 8.3 amps. Keep in mind that the wire feeding the heater must be a #10 because the breaker is rated at 25 amps. A wire's ampacity rating can be larger that the breaker amperage rating but never smaller. Example, a #14 rated at 15 amps or a #12 rated at 20 amps can not be connected to a 25 amp breaker. The 25 amp breaker does not trip until it reaches 25 amps well over the allowable amperage of the #14 amd #12 wire. This is why a #10 wire must be used as its rating is 30 amps.
What size breaker do you need for a well pump?
A breaker is based on the amperage that is drawn by the pump motor load. Find the full load amperage of the motor. The wire fed from the breaker has to be rated at 125% of the motors full load amperage. The breaker for motors have to be over sized, usually 250% of the motors full load amps.
How do you tell the meter amperage of your homes electric meter?
Your main breaker should tell you the amps of your panel.
What size breaker do you need for 5.7kw neff oven?
A breaker is sized by the wire size. The wire is sized by the amperage. The formula for amperage is I = W/E. Amps = Watts/Volts. As you can see with no voltage stated an answer can not be given.
What is the amperage rating of the mission essential power MEP circuit breaker of the secondary distribution center?
200 amps
What size breaker you would use for a 110 volt window air conditioning unit?
Breaker sizing is dependant on what the load amperage is that the breaker is connected to. If the amperage is not given but just the wattage, use this equation I = W/E. Amps = Watts/Volts. This air conditioner unit should be on a dedicated circuit receptacle. On these types of loads the conductor can only be loaded to 80% of the conductors rating. So a 15 amp breaker times 80% = 12 amps or Watts = Amps x Volts, 12 x 120 = 1440 watts. A 20 amp breaker times 80% = 16 amps or Watts = Amps x Volts, 16 x 120 = 1920. Once the breaker is sized remember to use the correct wire size to correspond with the amperage of the breaker.
What the breaker size require for kW?
The use of a breaker in a circuit is to protect the wire size used in the circuit from becoming overloaded. Using the wattage of the load does not help for breaker sizing because the breaker operates on amperage. Amperage can be found from wattage by using the following equation. I = W /E. Amps = Watts / Volts. As you can see the amperage can not be calculated because there is no voltage stated.
